TW201335336A - Luminescent material - Google Patents

Abstract

According to one embodiment, the luminescent material exhibits a luminescence peak in a wavelength ranging from 500 to 600 nm when excited with light having an emission peak in a wavelength ranging from 250 to 500 nm. The luminescent material has a composition represented by Formula 1 below: (M1-xCex)2yAlzSi10-zOuNw Formula 1 wherein M represents Sr and a part of Sr may be substituted by at least one selected from Ba, Ca, and Mg; x, y, z, u, and w satisfy following conditions: 0 < x ≤ 1, 0.8 ≤ y ≤ 1.1, 2 ≤ z ≤ 3.5, u ≤ 1 1.8 ≤ z-u, and 13 ≤ u+w ≤ 15.

Description

Luminescent material

Specific examples described herein outline luminescent materials, illuminating devices, and methods of making luminescent materials.

The white light-emitting device is constructed by combining, for example, a light-emitting material that emits red light by excitation with blue light, a light-emitting material that emits green light by excitation with blue light, and a blue LED. When a luminescent material that emits yellow light by excitation with blue light is used, the white light-emitting device can be constructed by using fewer luminescent material species. For example, an Eu-activated orthosilicate luminescent material is known as the yellow-emitting luminescent material.

There is an increasing need to emit yellow luminescent materials to improve temperature properties, quantum efficiency, and half-width of the luminescent emission spectrum.

According to a specific example, generally, the luminescent material exhibits an emission peak having a wavelength ranging from 500 to 600 nm when excited by light having a wavelength range of from 250 to 500 nm, and thus it is capable of being emitted in yellow-green. Light-emitting material to the orange area. Since the luminescent material of this specific example mainly emits light in the yellow region, it is hereinafter referred to as ytterbium emitting yellow luminescent material 〞. The luminescent material includes a parent material having a crystal structure substantially identical to that of Sr ₂ Si ₇ Al ₃ ON ₁₃ . The parent material is activated with Ce. The composition of the yellow-emitting luminescent material according to this specific example is represented by the following formula 1.

(M _1-x Ce _x ) _2y Al _z Si _10-z O _u N _w Formula 1 (wherein M represents Sr and a part of Sr may be substituted by at least one selected from the group consisting of Ba, Ca and Mg. x, y, z, u And w satisfy the following conditions: 0<x 1,0.8 y 1.1, 2 z 3.5, u 1,1.8 Zu and 13 u+w 15).

As shown in the above formula 1, the luminescent center element Ce replaces at least a part of M. M represents Sr and a part of Sr may be substituted with at least one selected from the group consisting of Ba, Ca and Mg. Even if the internal content of at least one selected from the group consisting of Ba, Ca, and Mg is 15 atom% based on the total amount of M, more desirably 10 atom% or less, it is not easy to produce a multiphase.

When at least 0.1 mol% of M is substituted with Ce, sufficient luminous efficiency can be obtained. The total amount of M can be replaced by Ce (x = 1). When x is less than 0.5, the reduced luminescence possibility (concentration sharp drop) can be suppressed as much as possible. Therefore, x is preferably from 0.001 to 0.5. When the luminescent center element Ce is contained, the luminescent material of this specific example exhibits luminescence in a yellow-green to orange region, that is, when excited with light having a wavelength range of 250 to 500 nm. Luminescence from a peak of 500 to 600 nm. In this regard, other elements (such as unavoidable impurities) containing 15 atom% based on the total amount of Ce, more desirably 10 atom% or less, do not impair the desired characteristics. Examples thereof include Tb, Eu, and Mn.

When y is less than 0.8, the crystal defects are increased, which leads to a decrease in efficiency. low. On the other hand, when y exceeds 1.1, the excess alkaline earth metal precipitates as a multiphase, which results in a decrease in luminescent properties. y is preferably from 0.85 to 1.06.

When z is less than 2, excess Si precipitates into a multiphase, which results in a decrease in luminescent properties. On the other hand, when z exceeds 3.5, excess Al precipitates into a multiphase, which results in a decrease in luminescent properties. z is preferably from 2.5 to 3.3.

When u exceeds 1, the efficiency is reduced with increased crystal defects. u is preferably from 0.001 to 0.8.

When (z-u) is less than 1.8, it becomes impossible to maintain the crystal structure of this specific example. In some cases, multiple phases are produced, and thus the effect of this specific example cannot be exerted. When (u + w) is less than 13 or exceeds 15, it is also impossible to maintain the crystal structure of this specific example. In some cases, multiple phases are produced, and thus the effect of this specific example cannot be exerted. (z-u) is preferably 2 or more and (u+w) is preferably from 13.2 to 14.2.

Since the luminescent material according to this specific example has all the conditions, it can emit light having a wide half width of the luminescent emission spectrum with high efficiency when excited with light having a wavelength range of from 250 to 500 nm. Therefore, white light with excellent color properties is obtained. Further, the yellow-emitting luminescent material according to this specific example has good temperature properties.

The yellow-emitting luminescent material according to this specific example can be obtained by using Sr ₂ Al ₃ Si ₇ ON ₁₃ group crystal as a basic material, replacing Sr, Si, Al, O or N (component elements of crystal) with other elements and dissolving other Obtained by a metal element such as Ce. The crystal structure can be modified by this substitution. However, an example in which the atomic position greatly changes to the degree of chemical bond splitting between the skeleton atoms is not common. The position of the atom is determined by the crystal structure, and the position is occupied by the atom and its coordination.

The effect of this specific example can be exerted without changing the basic crystal structure of the yellow-emitting luminescent material of this specific example. The lattice constant of the luminescent material according to this specific example and the chemical bond length of MN and MO (adjacent distance between atoms) may be different from those of Sr ₂ Al ₃ Si ₇ ON ₁₃ . If the variation is less than ± 15% of the Sr ₂ Al ₃ Si ₇ ON ₁₃ of the lattice constant and Sr ₂ Al ₃ Si ₇ ON ₁₃ chemical bonds in length (Sr-N and Sr-O), then this example is defined as No Change the crystal structure. The lattice constant can be determined by X-ray diffraction or neutron diffraction, and the chemical bond lengths of MN and MO (adjacent atomic distances) can be calculated from atomic coordination.

The crystal of Sr ₂ Al ₃ Si ₇ ON ₁₃ has an orthorhombic crystal system and its lattice constant is as follows: a = 11.8 angstroms, b = 21.6 Egypt c = 5.01 angstroms. Furthermore, the crystal system belongs to the space group Pna 21. The chemical bond lengths (Sr-N and Sr-O) in Sr ₂ Al ₃ Si ₇ ON ₁₃ can be calculated from the atomic coordination shown in Table 1 below.

Basically, the yellow-emitting luminescent material of this specific example has this crystal structure. When the change in the length of the chemical bond is out of range, the chemical bond splits and is converted into a different crystal. It is impossible to obtain the effects of the specific examples of the present invention.

The yellow-emitting luminescent material of this specific example includes an inorganic compound having a crystal structure substantially the same as that of Sr ₂ Al ₃ Si ₇ ON ₁₃ as a basic material and a part of the component element M is substituted with a luminescent center ion Ce. The composition of each element is specified within a predetermined range. In this example, the luminescent material exhibits preferred characteristics such as high efficiency, wide luminescence emission spectrum half-width, and temperature properties.

The crystal structure of Sr ₂ Al ₃ Si ₇ ON ₁₃ is based on the atomic coordination shown in Table 1 above as shown in Figs. 1A, 1B and 1C. 1A is a projection view in the axial direction c, FIG. 1B is a projection view in the axial direction b, and FIG. 1C is a projection view in the axial direction a. In the figure, 301 represents an Sr atom and is surrounded by Si atoms or Al atoms 302 and O atoms or N atoms 303. The crystal of Sr ₂ Al ₃ Si ₇ ON ₁₃ can be verified by XRD and neutron diffraction.

The luminescent material of this specific example has the composition represented by the above formula 1. The luminescent material has a specific diffraction angle (2θ) peak in the X-ray diffraction pattern using the Bragg-Brendano method of the Cu-Kα line. That is, it has at least 10 at 15.05-15.15, 23.03-23.13, 24.87-24.97, 25.7-25.8, 25.97-26.07, 29.33-29.43, 30.92-31.02, 31.65-31.75, 31.88-31.98, 33.02-33.12, 33.59- The peaks of the diffraction angle (2θ) of 33.69, 34.35-34.45, 35.2-35.3, 36.02-36.12, 36.55-36.65, 37.3-37.4 and 56.5-56.6.

The yellow-emitting luminescent material according to this specific example can be obtained by mixing and heating a raw material powder containing each element.

The M starting material may be selected from the group consisting of nitrides and carbides of M. The Al raw material may be selected from the nitrides, oxides, and carbides of Al, and the Si raw material may be selected from the nitrides, oxides, and carbides of Si. The raw material of the luminescent center element Ce may be selected from the oxides, nitrides and carbonates of Ce.

In this regard, nitrogen can be obtained by heating a nitride raw material or in a nitrogen-containing atmosphere, and oxygen can be obtained from the surface oxide film of the oxide raw material and the nitride raw material.

For example, an intended starting composition of Sr ₃ N ₂ , AlN, Si ₃ N ₄ , Al ₂ O ₃ , AlN, and CeO ₂ may be mixed, and Sr ₃ N ₂ may be replaced with Sr ₂ N, SrN, or a mixture thereof. In order to obtain a uniform mixed powder, it is desirable to dry-mix each raw material powder in an order of increasing mass.

The raw materials can be mixed using a mortar in, for example, a glove box. The mixed powder is placed in a crucible and heated under predetermined conditions to obtain a luminescent material according to this specific example. The material of the crucible is not particularly limited and its material may be selected from the group consisting of boron nitride, tantalum nitride, tantalum carbide, carbon, aluminum nitride, sialon, alumina, molybdenum, and tungsten.

It is desirable to heat the mixed powder at a pressure above atmospheric pressure. Heating at a pressure exceeding atmospheric pressure is advantageous in the fact that tantalum nitride is not easily decomposed. In order to suppress the decomposition of tantalum nitride at a high temperature, the pressure is preferably 5 atm or more and the heating temperature is preferably from 1,500 to 2,000 °C. When the heating is carried out under such conditions, the intended sintered body is obtained without causing any trouble such as sublimation of the material or product. The heating temperature is preferably from 1800 to 2000 °C.

In order to avoid oxidation of AlN, it is desirable to carry out the heating in a nitrogen atmosphere. The amount of hydrogen in the atmosphere can be as high as about 90 atom%.

Preferably, the mixed powder is heated at the above temperature for 0.5 to 4 hours, the sintered material is taken out from the crucible and pulverized and heated under the same conditions. A series of processes for removing, crushing and heating the powder are repeated up to about At 10 times, the advantages of a powder which is smallly fused between crystal particles and a uniform composition and crystal structure are easily obtained.

After heating, post-treatment, such as a cleaning method, is performed if necessary to obtain a luminescent material according to a specific example. For example, cleaning with pure water, acid cleaning or the like can be used as a cleaning method. Examples of useful acids include inorganic acids such as sulfuric acid, nitric acid, hydrochloric acid, and hydrofluoric acid; organic acids such as formic acid, acetic acid, and oxalic acid; and mixed acids thereof.

After cleaning with an acid, post-annealing may be performed if necessary. The post annealing treatment can be carried out, for example, in a reducing atmosphere containing nitrogen and hydrogen. Crystallinity and luminous efficiency are improved by performing post-annealing treatment.

A light-emitting device according to a specific example includes a light-emitting layer containing a light-emitting element of a light-emitting material and an excitation light-emitting material. Fig. 2 is a schematic view showing the structure of a light-emitting device according to a specific example.

In the light-emitting device shown in FIG. 2, lead 101 and 102 and a package cup 103 are arranged on a substrate 100. The substrate 100 and the package cup 103 are formed of a resin. The package cup 103 has a recess 105 whose upper portion is wider than the bottom portion thereof. The sidewall of the recess acts as a reflective surface 104.

The light-emitting element 106 is mounted as an Ag paste on the central portion of the nearly annular bottom portion of the recess 105. The light-emitting element 106 to be used emits light having an emission peak having a wavelength ranging from 400 to 500 nm. Examples of the light emitting element include a light emitting diode and a laser diode. In particular, a semiconductor light emitting element such as a GaN type LED is used, but is not particularly limited thereto.

The p and n electrodes (not shown) of the light-emitting element 106 are connected to lead 101 and lead 102 via bonding wires 107 and 108 formed by Au and the like, respectively. Pick up. The arrangement of the leads 101 and 102 can be arbitrarily modified.

It is also possible to use a flip tip structure in which the n-electrode and the p-electrode are disposed on the same surface thereof as the light-emitting element 106. In this example, it is possible to overcome wiring-related problems such as wire cutting or detachment and light absorption by the wires, thereby permitting the manufacture of a semiconductor light-emitting device having excellent reliability and luminous intensity. The following structure can be formed using a light-emitting element having an n-type substrate. The n-electrode is formed on the back surface of the n-type substrate of the light-emitting element and the p-electrode is formed on the upper surface of the p-type semiconductor layer stacked on the substrate. The n-electrode system is mounted on lead and the p-electrode is connected to other lead wires by wires.

The light-emitting layer 109 containing the luminescent material 110 according to a specific example is disposed in the recess 105 of the package cup 103. In the light-emitting layer 109, for example, 5 to 60% by mass of the light-emitting material 110 is contained in the resin layer 111 formed of the polyoxyn resin. As described above, the luminescent material according to this specific example contains Sr ₂ Al ₃ Si ₇ ON ₁₃ as a matrix material. This oxynitride has high covalent bonding properties. Therefore, the luminescent material according to this specific example is hydrophobic and has good compatibility with the resin. Therefore, the scattering at the interface between the resin layer and the luminescent material is significantly suppressed and the light extraction efficiency is improved.

The yellow-emitting luminescent material according to this specific example has good temperature properties and can emit yellow light having a wide half width of the luminescent emission spectrum with high efficiency. A white light-emitting device having excellent luminescent properties is obtained by combining with a light-emitting element that emits light having a wavelength range of from 400 to 500 nm.

The size and type of the light-emitting element 106 and the recess can be arbitrarily modified 105 size and shape.

The light-emitting device according to a specific example is not limited to the package cup type shown in Fig. 2, but can be arbitrarily modified. In particular, in the case of the bullet-shaped LED and the surface mount type LED, the same effect can be obtained using the specific example of the luminescent material.

Fig. 3 is a schematic view showing the structure of a light-emitting device according to another specific example. In the illustrated light-emitting device, p and n electrodes (not shown) are formed in predetermined regions of the heat dissipating insulating substrate 201 and the light emitting elements 202 are arranged on the substrate. The material material of the heat dissipating insulating substrate may be, for example, AlN.

One of the electrodes in the light-emitting element 202 is formed on the bottom surface and is electrically connected to the n-electrode of the heat-dissipating insulating substrate 201. The other electrode in the light-emitting element 202 is connected to a p-electrode (not shown) on the heat-dissipating insulating substrate 201 via a gold wire 203. As the light-emitting element 202, a light-emitting diode that emits light having a emission peak having a wavelength ranging from 400 to 500 nm is used.

The hemispherical inner transparent resin layer 204, the light emitting layer 205, and the outer transparent resin layer 206 are sequentially formed on the light emitting element 202. The inner transparent resin layer 204 and the outer transparent resin layer 206 may be formed using, for example, polyfluorene oxide. In the light-emitting layer 205, the yellow-emitting light-emitting material 207 of this specific example is contained in a resin layer 208 formed, for example, of a polyoxyxene resin.

In the light-emitting device shown in Fig. 3, the light-emitting layer 205 containing the yellow-emitting luminescent material according to this specific example can be simply produced using a procedure such as vacuum printing or dispensing by a dispenser. In addition, the light emitting layer 205 is sandwiched between the inner transparent resin layer 204 and the outer transparent resin layer 206, and thus The effect of improving extraction efficiency is obtained.

In this regard, the light-emitting layer of the light-emitting device according to this specific example may contain a light-emitting material that emits green light by excitation with blue light and a light-emitting material that emits red light by excitation with blue light, together with the light-emitting material that emits yellow light of this specific example. In this example, a white light-emitting device with excellent color rendering properties is obtained.

Even when the yellow-emitting luminescent material according to this specific example is excited with light having a wavelength range of from 250 to 400 nm in the ultraviolet region, yellow luminescence is also obtained. Therefore, the white light-emitting device can be constructed by, for example, combining a light-emitting material according to this specific example, a light-emitting material that emits blue light by ultraviolet light, and a light-emitting element such as an ultraviolet light-emitting diode. The luminescent layer in the white illuminating device may contain a luminescent material that emits ultraviolet light to emit light having a peak of another wavelength, together with the yellow-emitting luminescent material of this specific example. Examples thereof include a luminescent material that emits red light by ultraviolet light and a luminescent material that emits green light by ultraviolet light.

As described above, the luminescent material of this specific example has good temperature properties and can emit yellow light having a wide half width of the luminescent emission spectrum with high efficiency. When the yellow-emitting luminescent material of this specific example is combined with a light-emitting element that emits light having a wavelength of from 250 to 500 nm, several luminescent materials can be used to obtain a white light-emitting device having excellent emission properties.

Specific examples of luminescent materials and illuminating devices are shown below.

Sr ₃ N ₂ , CeO ₂ , Si ₃ N ₄ and AlN were prepared into Sr raw materials, Ce raw materials, Si raw materials and Al raw materials, and the materials were weighed in a vacuum glove box. The blending masses of Sr ₃ N ₂ , CeO ₂ , Si ₃ N ₄ and AlN were 2.680 grams, 0.147 grams, 5.086 grams and 1.691 grams, respectively. The blended raw material powder was dry blended in an agate mortar.

The obtained mixture was placed in a boron nitride (BN) crucible and heated at 1800 ° C for 2 hours under a nitrogen atmosphere of 7.5 atm. The sintered material was taken out of the crucible and broken in an agate mortar. The crushed and sintered material was placed in a crucible and heated at 1800 ° C for 2 hours. A series of processes of taking out, crushing, and heating the powder were repeated twice more to obtain the luminescent material of Example 1.

The luminescent material obtained is a powder having a yellow solid color. When it was excited by black light, it was confirmed to be yellow light.

The XRD pattern of the luminescent material is shown in FIG. The XRD pattern is determined herein by reference to X-ray diffraction using the Bragg-Brendano method of the Cu-Kα line. As shown in Figure 4, the peaks appear at 15.05-15.15, 23.03-23.13, 24.87-24.97, 25.7-25.8, 25.97-26.07, 29.33-29.43, 30.92-31.02, 31.65-31.75, 31.88-31.98, 33.02-33.12, Diffraction angles (2θ) of 33.59-33.69, 34.35-34.45, 35.2-35.3, 36.02-36.12, 36.55-36.65, 37.3-37.4 and 56.5-56.6.

The relative intensities of the peaks shown in Figure 4 are summarized in Table 2 below.

The luminescence emission spectrum is shown in Fig. 5 when the luminescent material is excited by light from a xenon lamp dispersed at an emission wavelength of 450 nm. In Figure 5, the emission with a narrow half width near 450 nm is the excitation light reflection, not the luminescent material. It has been confirmed to have a high luminous intensity of a peak wavelength of 551 nm. The half width calculated by the instantaneous multi-channel spectrometer was 117 nm. The half width is one of the indicators of the color properties of white light produced by the illuminating device. Generally, when the half width is wider, white light of excellent color rendering properties is easily obtained. Since the half width is 117 nm, it is recommended to use the luminescent material of Example 1 to easily obtain white light of excellent color rendering properties.

Figure 6 shows the temperature properties of the luminescent material. The temperature properties were determined in the following manner. The luminescent material is heated by a heater and the luminescence intensity (I _T ) at a predetermined temperature of T ° C is obtained. Luminous intensity was measured using an instantaneous multichannel spectrometer. The luminescence intensity at 25 ° C (I ₂₅ ) was used and calculated from the formula of (I _T /I ₂₅ )x100. As shown in Fig. 6, it was found that a strength retention of 0.88 or more was obtained at 150 ° C and the reduced luminescence intensity was small, even if the temperature was increased.

A light-emitting device having the structure shown in Fig. 3 was produced using the luminescent material of this example.

An AlN substrate having 8 mm 2 was prepared as the heat dissipating insulating substrate 201 in which p and n electrodes (not shown) were formed in a predetermined region. A light-emitting diode having an emission peak of a wavelength of 460 nm was used as the light-emitting element 202 to be bonded to the substrate by solder. One of the electrodes in the light-emitting element 202 is formed on the bottom surface and is electrically connected to the n-electrode of the AlN substrate 201. The other electrodes in the light-emitting element 202 are connected via a gold wire 203 to a p-electrode (not shown) on the AlN substrate 201.

The inner transparent resin layer 204, the light-emitting layer 205, and the outer transparent resin layer 206 sequentially form a hemispherical shape on the light-emitting element 202 and the light-emitting device of this example is obtained. Polyoxyphthalic resin is used as the material of the inner transparent resin layer 204 and the layer is formed by a dispenser. The light-emitting layer 205 was formed using a transparent resin containing 50% by mass of the luminescent material of this example. The transparent resin used is a polyoxymethylene resin. Further, an outer transparent resin layer 206 is formed on the light-emitting layer 205 using the same polyoxyxene resin as the example of the inner transparent resin layer 204.

When the illuminating device was placed in an integrated sphere and driven at 20 mA and 3.3 volts, the color temperature was 6300 K, the luminous efficiency was 180 lm/W, and Ra was equal to 76. Color temperature, luminous efficiency, and Ra are obtained from an instantaneous multi-channel spectrometer.

The white light-emitting device of this example is a combination of the luminescent materials of this example. Obtained with a blue LED having an emission peak of 460 nm wavelength. The use of white light-emitting devices allows the formation of white LEDs for high power applications with high luminous efficiency and high color rendering properties.

The luminescent materials of Examples 2 to 17 and Comparative Examples 1 and 2 were obtained by the same procedure as described in Example 1, except that the materials and blending qualities were changed, as shown in Tables 3 and 4 below.

The luminescent materials of Examples 2 to 17 were powders having a yellow solid color. When these were excited by black light, it was confirmed to be yellow light. The XRD patterns of the luminescent materials are shown in sequence in Figures 7-22. Ten peaks in descending order of intensity selected from the XRD pattern were confirmed to be the strongest peaks. The diffraction angle (2θ) is represented by 〝○〞 in Tables 5 and 6.

In any of the luminescent materials in the examples, the 10 strongest peaks were found to be 15.05-15.15°, 23.03-23.13°, 24.87-24.97°, 25.7-25.8°, 25.97-26.07°, 29.33-29.43°, 30.92. -31.02°, 31.65-31.75°, 31.88-31.98°, 33.02-33.12°, 33.59-33.69°, 34.35-34.45°, 35.2-35.3°, 36.02-36.12°, 36.55-36.65°, 37.3-37.4° and 56.5 Any of the diffraction angles (2θ) of -56.6°.

The luminescent properties of the luminescent materials of Examples 2 to 17 and the luminescent materials of Comparative Examples 1 and 2 were examined in the same manner as described above. The results are summarized in Table 7 below together with the luminescent properties of the luminescent material of Example 1. The intensity in Table 7 shows the relative intensity when the luminous intensity of Example 1 was defined as 1. The chromaticity (Cx, Cy) was obtained with an integrated spherical total luminescence analyzer.

As shown in Table 7 above, the luminescent materials of Examples 1 to 17 had luminescence peaks having a wavelength ranging from 544 to 555 nm and obtained a high luminescence intensity of 0.85 or more. Further, a wide luminescence having a half width of the luminescent emission of 116 nm or more was obtained. On the other hand, the luminescent materials of Comparative Examples 1 to 2 had an illuminating intensity of 0.32 to 0.52 and sufficient brightness was not obtained.

The same procedure as above was examined for the temperature properties of the luminescent materials of Examples 2 to 17. All of the luminescent materials of Examples 2 to 17 were confirmed at 150 ° C It has a strength retention of 0.81 or more and has good temperature properties, similar to the example of Example 1. Some results are shown in Table 8 below and Figure 23.

When the luminescent materials of Examples 1 to 17 and Comparative Examples 1 to 2 were chemically analyzed by inductively coupled plasma (ICP), the results are summarized in Table 9 below. The numerical values shown in Table 9 are the molar ratios obtained by setting the sum of the amount of Al and the amount of Si to 10 and normalizing the amount of the analysis element.

x, y, z, u, and w in Table 9 correspond to x, y, z, u, and w in the following Formula 1.

(M _1-x Ce _x ) _2y Al _z Si _10-z O _u N _w

As shown in the above Table 9, in any of the luminescent materials of Examples 1 to 17, x, y, z, u, and w are within the following ranges: 0 < x 1,0.8 y 1.1, 2 z 3.5, u 1,1.8 Zu and 13 u+w 15.

Since the luminescent material of the example has a predetermined composition, it can obtain yellow light having a wide half width of the luminescent emission spectrum with high efficiency and has good temperature properties. On the other hand, in Comparative Example 1 in which sufficient brightness was not obtained, z-u was as small as 1.39 to 1.41. Further, in Comparative Example 2, z is as large as 3.56 and u is as large as 2.17.

Next, an Eu-activated orthosilicate luminescent material obtainable on the market was prepared as the luminescent material of Comparative Example 3.

The luminescent materials of Comparative Examples 4 to 11 were synthesized in the same composition as the luminescent material of Example 1, except that each of the following compositions in Formula 1 was changed as shown in Table 10 below.

The XRD patterns of the luminescent materials of Comparative Examples 3 to 11 were measured in the same manner as described above. As a result, in the luminescent materials of the comparative examples, the peaks do not always appear at 15.05-15.15, 23.03-23.13, 24.87-24.97, 25.7-25.8, 25.97-26.07, 29.33-29.43, 30.92-31.02, 31.65-31.75, Diffraction angles (2θ) of 31.88-31.98, 33.02-33.12, 33.59-33.69, 34.35-34.45, 35.2-35.3, 36.02-36.12, 36.55-36.65, 37.3-37.4 and 56.5-56.6.

Further, the luminescent materials of Comparative Examples 3 to 11 were excited by emitting light having a wavelength of 450 nm in the same manner as described above. The luminescent properties were examined and the temperature properties of each luminescent material were determined. It was confirmed that all of the luminescent materials of the comparative examples were impossible to combine luminescent properties and temperature properties.

In particular, the Eu-activated protoporphydate luminescent material (Comparative Example 3) has a half width as narrow as about 70 nm. Even if a luminescent material is combined with a blue light-emitting diode, a light-emitting device having good color-developing properties is not obtained. In addition, the luminous intensity at high temperatures is significantly reduced. In the case of a high output lighting device having a power supply of about 300 milliwatts or more, the efficiency is reduced.

When the y value in Formula 1 is less than 0.8 (Comparative Example 4), the amount of Sr+Ce is too small and the crystallinity is lowered, resulting in low efficiency. On the other hand, when the y value exceeds 1.1 (Comparative Example 5), the amount of Sr+Ce is too large and the excess Sr+Ce forms a multi-phase, resulting in low efficiency.

When the z value in Formula 1 is less than 2 (Comparative Example 6), the amount of Al is too small. Therefore, the crystal structure cannot be maintained and converted into a different crystal structure, resulting in Insufficient features. On the other hand, when the z value exceeds 3.5 (Comparative Example 7), the amount of Al is too large and the crystal structure is converted into a crystal structure containing a large amount of Al, resulting in insufficient characteristics.

When the u value in Formula 1 is 1 or more (Comparative Example 8), the amount of O is too large. Therefore, the covalent bonding property is lowered, the wavelength is shortened, and the efficiency is lowered, resulting in insufficient temperature properties. On the other hand, when the z-u value is less than 1.8 (Comparative Example 9), the amount of O compared with Al is too large, the crystal structure is not maintained, and it is converted into a different crystal structure. Therefore, the desired characteristics are not obtained.

When the value of u + w in Formula 1 is less than 13 (Comparative Example 10), the amount of anion is too small and the charge balance is broken. Therefore, the crystal structure cannot be maintained and converted into a different crystal structure, resulting in insufficient characteristics. On the other hand, when the u+w value exceeds 15 (Comparative Example 11), the amount of anions is too large and the charge balance is broken. Therefore, the crystal structure cannot be maintained and converted into a different crystal structure, resulting in insufficient characteristics.

According to a specific example of the present invention, it is possible to provide a luminescent material which has good temperature properties and can emit yellow light having a wide half width of a luminescent emission spectrum with high efficiency. The combination of the yellow-emitting luminescent material and the blue LED of this specific example enables a white light-emitting device having excellent color rendering properties and good luminescent properties to be obtained.

The specific examples are presented by way of example only and are not intended to limit the scope of the invention. In fact, the novel embodiments described herein may be embodied in a variety of other forms, and various other omissions, substitutions and changes can be made without departing from the spirit of the invention. It is intended to be in the scope of the attached patent application and its equivalent. Such forms or modifications of the cover will fall within the scope and spirit of the invention.

100‧‧‧Substrate

101, 102‧‧‧ lead

103‧‧‧Package cup

104‧‧‧Reflective surface

105‧‧‧ recess

106, 202‧‧‧Lighting elements

107, 108‧‧‧ Bonding wire

109‧‧‧Lighting layer

110‧‧‧ luminescent materials

111,208‧‧‧ resin layer

301‧‧‧Sr atom

302‧‧‧Si atom or Al atom

303‧‧‧O atoms or N atoms

201‧‧‧Heat dissipative insulation substrate

203‧‧‧ Gold wire

204‧‧‧Internal transparent resin layer

205‧‧‧Yellow luminescent layer

206‧‧‧External transparent resin layer

207‧‧‧Silver emitting yellow light

1A, 1B and 1C are views showing a crystal structure of Sr ₂ Al ₃ Si ₇ ON ₁₃ ; Fig. 2 is a schematic view showing a structure of a light-emitting device according to a specific example; and Fig. 3 is a view showing a light-emitting device according to another specific example Figure 4 is a view showing the XRD pattern of the luminescent material of Example 1, Figure 5 is a view showing the luminescence emission spectrum of the luminescent material of Example 1, and Figure 6 is a diagram showing the temperature properties of the luminescent material of Example 1; The XRD pattern of the luminescent material of Example 2 is shown; FIG. 8 shows the XRD pattern of the luminescent material of Example 3; FIG. 9 shows the XRD pattern of the luminescent material of Example 4; FIG. 10 shows the XRD pattern of the luminescent material of Example 5; 6 shows the XRD pattern of the luminescent material; FIG. 12 shows the XRD pattern of the luminescent material of Example 7; FIG. 13 shows the XRD pattern of the luminescent material of Example 8; FIG. 14 shows the XRD pattern of the luminescent material of Example 9; XRD pattern of the luminescent material; Fig. 16 shows the XRD pattern of the luminescent material of Example 11; Fig. 17 shows the XRD pattern of the luminescent material of Example 12; Fig. 18 shows the XRD pattern of the luminescent material of Example 13, and Fig. 19 shows the luminescent material of Example 14. X RD pattern; FIG. 20 shows an XRD pattern of the luminescent material of Example 15; FIG. 21 shows an XRD pattern of the luminescent material of Example 16, FIG. 22 shows an XRD pattern of the luminescent material of Example 17, and FIG. 23 shows the luminescent material of Example 13. A diagram of the nature of temperature.

100‧‧‧Substrate

101‧‧‧ lead

102‧‧‧ Lead

103‧‧‧Package cup

104‧‧‧Reflective surface

105‧‧‧ recess

107‧‧‧bonding line

108‧‧‧bonding line

109‧‧‧Lighting layer

110‧‧‧ luminescent materials

111‧‧‧ resin layer

106‧‧‧Lighting elements

Claims (15)

A luminescent material exhibiting an emission peak having a wavelength ranging from 500 to 600 nm when excited by light having a wavelength range of from 250 to 500 nm, the luminescent material having a composition represented by the following formula 1: (M _1-x Ce _x ) _2y Al _z Si _10-z O _u N _w Formula 1 wherein M represents Sr and a part of Sr may be substituted with at least one selected from the group consisting of Ba, Ca and Mg; x, y, z, u and w satisfy The following conditions: 0<x 1,0.8 y 1.1, 2 z 3.5, u 1,1.8 Zu and 13 u+w 15. The luminescent material according to claim 1, wherein the luminescent material has at least 10 in the X-ray diffraction using the Bragg-Brendano method of Cu-Kα line at 15.05-15.15, 23.03-23.13, 24.87-24.97 , 25.7-25.8, 25.97-26.07, 29.33-29.43, 30.92-31.02, 31.65-31.75, 31.88-31.98, 33.02-33.12, 33.59-33.69, 34.35-34.45, 35.2-35.3, 36.02-36.12, 36.55-36.65, 37.3 The peak of the diffraction angle (2θ) of -37.4 and 56.5-56.6. A luminescent material according to the first aspect of the patent application, wherein x is from 0.001 to 0.5. A luminescent material according to the first aspect of the patent application, wherein y is from 0.85 to 1.06. According to the luminescent material of claim 1, wherein z is from 2.5 to 3.3. According to the luminescent material of claim 1, wherein u is from 0.001 to 0.8. A luminescent material according to the first aspect of the patent application, wherein z-u is 2 or more. According to the luminescent material of claim 1, wherein u+w is from 13.2 to 14.2. The luminescent material according to any one of claims 1 to 8, wherein 15 atom% or less of Ce is replaced with another element. The luminescent material according to any one of claims 1 to 9, wherein the luminescent material has an orthorhombic crystal structure. A light-emitting device comprising: a light-emitting element that emits light having a wavelength range of from 250 to 500 nm; and a light-emitting layer comprising the light-emitting material, the light-emitting material receiving light from the light-emitting element The luminescent material that emits yellow light and emits yellow light includes the luminescent material of any one of claims 1 to 10. The illuminating device of claim 11, further comprising: a heat dissipating insulating substrate on which the luminescent element is disposed, wherein the luminescent layer is hemispherical. The illuminating device of claim 11, wherein the luminescent layer further comprises at least one luminescent material selected from the group consisting of a luminescent material that emits green light by blue light and a red light that emits red light. According to the illuminating device of claim 11, wherein the hair luminaire The light element emits ultraviolet light having a peak having a wavelength ranging from 250 to 400 nm, and the light emitting layer further includes a light emitting material that emits blue light by ultraviolet light. A method of producing a luminescent material according to any one of claims 1 to 10, which comprises: an M material selected from the group consisting of nitrides and carbides of M, a nitride selected from the group consisting of nitrides, oxides and carbides of Al The Al raw material, the Si raw material selected from the nitrides, oxides and carbides of Si are mixed with the Ce raw material selected from the oxides, nitrides and carbonates of Ce to obtain a mixture; and the mixture is heated.